Published online by Cambridge University Press: 20 November 2018
We study the representations of extended affine Lie algebras $s{{\ell }_{\ell +1}}\left( {{\mathbb{C}}_{q}} \right)$ where
$q$ is
$N$-th primitive root of unity (
$({{\mathbb{C}}_{q}}$ is the quantum torus in two variables). We first prove that
$\oplus \,s{{\ell }_{\ell +1}}\left( \mathbb{C} \right)$ for a suitable number of copies is a quotient of
$s{{\ell }_{\ell +1}}\left( {{\mathbb{C}}_{q}} \right)$. Thus any finite dimensional irreducible module for
$\oplus \,s{{\ell }_{\ell +1}}\left( \mathbb{C} \right)$lifts to a representation of
$s{{\ell }_{\ell +1}}\left( {{\mathbb{C}}_{q}} \right)$. Conversely, we prove that any finite dimensional irreducible module for
$s{{\ell }_{\ell +1}}\left( {{\mathbb{C}}_{q}} \right)$ comes from above. We then construct modules for the extended affine Lie algebras
$s{{\ell }_{\ell +1}}\left( {{\mathbb{C}}_{q}} \right)\oplus \mathbb{C}{{d}_{1}}\oplus \mathbb{C}{{d}_{2}}$ which is integrable and has finite dimensional weight spaces.